Efhw Grounding

net is a Web site dedicated to ham radio (amateur radio). I've settled on a EFHW-8010P from myantennas. Karakteristik antenna ini adalah impedansinya tinggi pada orde kilo ohm dan tidak memerlukan grounding yang rumit, sedangkan bentuk gelombang radiasi yang dipancarkan serta pola distribusinya sepanjang kawat antenna sama dengan. For example, I have found that my 20m vertical end fed half wave antenna with the bottom 1m from the ground is an extremely effective antenna. This is an End-Fed Half-Wave (EFHW*) antenna for 40/20/15 and 10m bands. To continue with your YouTube experience, please fill out the form below. Here is a sure fire way to make end fed half wave antennas fed with a 50 ohm coupler work - without long radials, elaborate grounds, chokes, voodoo, etc. The “QSO King” is an end-fed antenna, but it’s not an end-fed, half-wave (EFHW) antenna that most us think about when we hear the term “end-fed. I have seen a lot of discussion on EFHW antennas on a single pole, but not much on field antennas on multiple crappie poles. Thus, the EFHW has a decisive advantage of groundwave radiation over long distances, which is not achieved by other radialless antenna shapes. Hi, Thanks for all previous help on my antenna questions. amateurradio) submitted 1 year ago by eve-dude I'm trying to decide what is best practice for the ground/counter-poise on my EFHW. Note that it is modelled as a vertical with the feedpoint between the bottom of the antenna and ground. Thanks to Jon AF7TS for the suggestion and discussions that led to this article. ham radio - AFTER the zombie apocalypse, The prepp Ham Radio - Ground spike antenna. Easy to Install and Use KM5M on 23rd Apr 2014 The NI4L end-fed 40-6m dipole antenna is just about perfect for portable operation. EFHW End Fed Halfwave Antenna is a curation of 25 resources about , 20m Half-Wave End Fed, The EFHW Antenna, End Fed Half-Wave Antennas, EFHW matching unit, End Fed Half Wave Antenna Coupler. I am guessing that it's the convenience of the EFHW that makes it such a favourite. Keep the antenna as high off the floor as possible. EFHW Inverted-V supported by tree. Wire Supported by Any Convenient Means. 5MHz) therefore also resonant on second, third and fourth harmonics etc. Due High Impedance feed point, the antenna is less. 102 feet long, shorter than 80 Meter dipole. A vertical seemed the obvious answer, a naturally low-angle radiator. Both techniques could be combined so an EFHW for 40-30-20 (for example) would be easy to make. https://www. I may hang not just the center, but also the far end of the wire as high as possible to lower ground losses. 005S/m, 13dk. 7 meter ( 2. The ground wiring and everything connected to it is every bit as much a part of the Marconi antenna system as is the live element. When I experimented with an EFHW with and without GP I was careful to follow the same practice I used with the 5/8 GP - isolate the antenna halves from each other, provide positive ground potential through the matching network, and keep working to tune the radials lengths, tap point on the matching inductor, and amount of capacitance by adjusting the variable cap in the. If someone would like to produce radiation charts based on the dimensions discussed and for various heights above ground, I am happy to include the charts here. Post # 144 MHz 4 element yagi - dimensions. The ground plane is assumed to be perfectly electrically conducting (PEC). The coax will be about 23 cm in total resulting in 22pF. I have various versions but I tend to grab the PackTenna version most often for 20m. 2m ground clearance, apex 1m below the top of pole (for stability) 84m was "guestimated" as the starting point for the overall size of the loop. My inverted-V at 40 ft. •DC voltage creates an electric field (not an electromagnetic wave) •DC current creates a magnetic field (not an electromagnetic wave) 2) Every antenna must have a place for a field to originate AND terminate. This allows the components to all be constructed over a common ground plane. Google "EFHW" along with their call signs and you will get there. It is only 10′ off the ground at that end, but rises up to about 30 feet in the tree at the far end. Applying a feed to any antenna in NEC or any electromagnetic simulation software is about a simple a task as can be conceived by placing a “source” of near infinitesimal size inline with a dipole element. While 1/8th wave works reasonably well, better coverage is obtained if the antenna is mounted at about 1/20th wavelength above ground. The first thing. 5mm plug (I have one of these but haven't yet found a source for a new one; I might have to make one) in case I would want to (or need to) use the. A half-wave at the lowest band of interest will also work well on all harmonically-related bands which has become particularly attractive to those wanting a quick portable wire antenna. The Shunt-fed Tower, an effective Low Band Antenna, uses your beam as a capacitive top-hat and only needs a simple feed network and a good ground system to work DX on 80M and 160M. Thanks to Jon AF7TS for the suggestion and discussions that led to this article. I wanted high efficiency 40 Meter antenna with low-angle radiation. Post #1236. The advantage of a coil is that it can afford some additional lighting protection, shunting some of the strike current to ground at the antenna so surge protection farther down the feedline has to deal with less. Config 1: No ground, use coax shield as counterpoise. Even keying the microphone and saying nothing resulted in noise on 40m. 2mm insulated wire run up one pole, across to the other then down the other. Figure 1 below shows the business end of the end-fed dipole with source and series reactance Xs (a capacitance) combine to yield a 50 ohm feed impedance for the source. Somewhere on the internet I read that a small counterpoise is optimal, so chances are it was omitted in the design you mention to make the antenna smaller, or because it didn't offer a noticeable improvement. 2E0VOV does an excellent job of describing both the theory, design, and operation of this antenna, which is based on the "Par Endfedz" multiband QRP antenna. Here it is set up in the garden for testing on 145. When I experimented with an EFHW with and without GP I was careful to follow the same practice I used with the 5/8 GP - isolate the antenna halves from each other, provide positive ground potential through the matching network, and keep working to tune the radials lengths, tap point on the matching inductor, and amount of capacitance by adjusting the variable cap in the. Daniel S • February 17, 2019 2:08 AM It seems to me that the main problem is not that the cable has the properties it’s got, but that any device plugged in to the port automatically gets. Antenna Notes from the Field. I’d also take a pair of solder-less alligator clips (less than $1 each, many sources) and a solder-less 3. Horizontal is 90°. 05 wavelength counterpoise, however the performance on the air is the same. The external environment such as elevation, ground type and angles are critical to measuring an end fed when close to ground. Describe your experience with the EFHW-8010 8-band End Fed Half Wave antenna and tell us why you give it the rating you did (required). Certainly the complex impedance at the end of the EFHW will change and I would bet my shoes that it will be out of the 1:2 SWR range of my back yard setup the wire has been cut to and the transformation rate of the UNUN was tuned to. Easy to Install and Use KM5M on 23rd Apr 2014 The NI4L end-fed 40-6m dipole antenna is just about perfect for portable operation. A 5 elements (free space 8,5 dBD gain) placed 9 meters above the ground would have 13,06 dBD gain at 16 degrees. COM Firearm Discussion Forums, Everything. Resources listed under EFHW Antenna category belongs to End-Fed main collection, and get reviewed and rated by amateur radio operators. There is no significant edge for the link dipole in performance. Don’t forget the chassis ground to the solder tab that comes with the SO-239 socket. 5 - 30mHz This is a 200 Watt PEP step up transformer for end fed full and half wave antennas without radials, designed as a 200 Watt PEP upgrade by PA0EJH for the originaly Par Electronics designed 25 Watt HF endfedz multiband end fed antenna. Counterpoise wire(s) close to or laying on the ground will couple and become radials with reduced efficiency. 18 thoughts on “ NVIS Antennas ” Leonard Hunsicker on August 26, 2019 at 3:06 PM said: I have been using a 1/2 wave 75 meter Inv- Vee up abt 17 feet directly above a couple mile long 4-wire barbed wire fence. 3 SWR on 40M using the 40M EFHW. If you live in a space restricted location or are under a HOA restriction, you may be able to mount an antenna outside. Feeding an End Fed Half Wave Antenna ½ l •May work (somewhat) since the coax shield acts as a counterpoise: •Coax shield provides the return path for the RF field •Performance will vary with X, proximity to ground, etc •SWR losses on the coax can be a problem •Tuner needs to be at the base of the antenna X RF Field Tuner. Shipping is UPS Ground or USPS. It performs poor above "bad" ground like desert. Hamsticks are classified as helical wound 4 foot antennas that have a tuning tip on the end. Hi Michael, Definitely a typo, I am unsure why I have 1. Assembly Photos KH6MB EFHW Tuner. Using a power transformer at a frequency it wasn't designed for. I had some struggles with this matchbox due to excess stray capacitance as well as using some low quality binding posts for the ground and antenna connections that caused some intermittent connections. After reading the article Antennas and the QRP Operator by Jim Thompson, W4THU, in Low Power Communications, Volume 2 (edited by Rich Arland, K7YHA), I built a 20m Extended Double Zepp. Far end is about 3ft off the ground. Should work on 160 and all the way up to 6 meters with a 81. No the inverted L feed point is at ground zero. I’ve made quite a few 64:1 transformers on a tiny FT-114A-43 core that will handle 100w SSB and it fits into a box slightly bigger than a Zippo lighter. Here is a sure fire way to make end fed half wave antennas fed with a 50 ohm coupler work - without long radials, elaborate grounds, chokes, voodoo, etc. Using a watering can, even children can sink an 8 foot ground rod into the ground. For most hams, an end-fed antenna is and "end-fed, half-wave," or EFHW, antenna. 4 metre length of silicon insulated 18 AWG multi-strand copper wire supported by a 9 metre telescopic pole. 10:00am John Kludt, K4SQC. When SWR is higher than 2:1 or antenna is used on the non-resonant frequency of the wire radiator, power reduction is recommended due to additional mismatch losses and the possibility to overheat the. Basically, a piece of wire that is a half wavelength of the band you intend to operate. Daniel S • February 17, 2019 2:08 AM It seems to me that the main problem is not that the cable has the properties it’s got, but that any device plugged in to the port automatically gets. This is an End-Fed Half-Wave (EFHW ) antenna for 80/40/30/20/17/15/12 and 10m bands. End-fed horizontal wire, an EFHW, offers the perfect solution for a wide range of ham activities. The last few years have seen a resurgence of interest in the end fed half-wave wire EFHW antenna. A simple guide to selecting power MOSFETs. The advantage of a coil is that it can afford some additional lighting protection, shunting some of the strike current to ground at the antenna so surge protection farther down the feedline has to deal with less. Granted the ground is smart to have but sometimes on my portable trips that just isn't easy to do. ARDUINO ATU for EFHW 20/40m antenna & Icom TRX. For most hams, an end-fed antenna is and "end-fed, half-wave," or EFHW, antenna. The soil here is 99% clay about 8" down so it gets really unpleasant to work in quite quickly. The efhw fixed component doubler definitely works in the field without having to tweek it. There was an issue with the ISS VHF downlink during this pass, so the contact was rescheduled to the next pass, at 2015 UTC. By John Portune W6NBC. Post #1231. If the antenna is being used at a temporary location the wire can be very quickly erected from a window in the building to a nearby support or tree without having to run co-ax cable or run earth radials. G0KYA's HF End Fed Half Wave (EFHW) antenna - construction details Introduction The EFHW monoband matching unit (inspired by AA5TB) allows for a half wavelength of wire to be connected, giving a 50 Ohm impedance match to the transmitter (without a ground plane or ATU) at the frequency of operation. However, about 2/3 of the total inverted-V signal is lost to ground when compared to a straight EFHW wire at 40 feet; from 6. 5″) segments into a λ/2 antenna (connected to the EFHW transformer), and the remaining three can be folded over, plugged in to themselves and used as three double-wire λ/4 ground radials. Thanks to Jon AF7TS for the suggestion and discussions that led to this article. I found that putting 220pf in parallel with the input (TX side) brought my 20M SWR down to 1. My house is on a slab and there is no visible ground rod anywhere around the house. The last few years have seen a resurgence of interest in the end fed half-wave wire EFHW antenna. https://www. 5mm is a minimum. net provides recognition and enjoyment to the people who use, contribute, and build the site. Shipping is UPS Ground or USPS. The EFHW - an efficient monoband end-fed half wave for 10m, 20m or any other HF band Update: A detailed description and construction details are now available for download (PDF). EFHW-8010 Multi-Band End Fed Half Wave Antenna-NO TUNER NEEDED! This is an End-Fed Half-Wave (EFHW*) antenna for 80/40/30/20/17/15/12 and 10m bands. The cost of materials for this build, including doors and windows, was around $2,200, which was about the same price as the install would have been on one of this. Using a watering can, even children can sink an 8 foot ground rod into the ground. I support the feedpoint on a push-up painters pole on the rear of an RV trailer and drape the wire over a nearby tree branch. 2m ground clearance, apex 1m below the top of pole (for stability) 84m was "guestimated" as the starting point for the overall size of the loop. Question on grounding EFHW (self. GROUND This antenna is from Paolo 1DX101, The 3 elements Delta Loop has a boomlenght of 5,4 meters. EFHW antenna for 40-10m qrp I had a BN43-202 core in stock and attempted to try to create a small QRP EFHW transformer from 7 - 29 MHz. The current horizontal EFHW is up about 35 feet in a tree. I used a 2' long wire braid and a 1' long stake in the ground to create about 3' (1m) of return ("counterpoise"). Proper lightning protection is an important aspect of designing a safe amateur radio station. How to Install Ham Antenna Ground Radials. Setting out to explore the world out of EFHW antennas that have dominated the discussions nowadays. These values assume that the antenna tuner is placed at the feed point of the antenna and that a suitable ground is provided. 2001 The 40 Meters band stealth vertical antenna by K7ZB “You’re 30dB over 9 here…” So goes the consistently fine signal reports received from around the USA and beyond – on 40 meters at the peak of Sun Spot Cycle 23. A simple guide to selecting power MOSFETs. No ground plane or counterpoise is needed. Resistor combinations: How many values using 1kohm resistors? Reduce acoustic noise from capacitors. 5 metres to 6. Updated: 2018-07-09. Update June 2018: I'm still using this matching unit regularly and most recently have started using it with another multi-band end-fed design which is even simpler than the trapped EFHW. Matching Unit. 3 SWR on 40M using the 40M EFHW. care with grounding. It is resonant Half wave on 80m (3. Thus, the EFHW has a decisive advantage of groundwave radiation over long distances, which is not achieved by other radialless antenna shapes. Grounding the EFHW Antenna. The missmatch loss between 50 and 75 ohm is something like 0. The resulting pattern on 20m is a squashed donut of sorts with a peak gain of +0. Wire Supported by Any Convenient Means. The radiation pattern changes from band to band. ” I’m not even sure what you’d call this antenna, except maybe an end-fed random wire, with a balun connected to it to try to bring the SWR down to something than a rig’s internal tuner. HF is hard: Perhaps it is better to say, if you do not do it a lot, HF can be challenging. com/watch?v=MzfQybYMlUc 20 meter half wave antenna installed at 7' high with horizontal coax feed for testing RF curr. When I experimented with an EFHW with and without GP I was careful to follow the same practice I used with the 5/8 GP - isolate the antenna halves from each other, provide positive ground potential through the matching network, and keep working to tune the radials lengths, tap point on the matching inductor, and amount of capacitance by adjusting the variable cap in the. As for the ground rod, my understanding is that it helps with safety (static etc. It is a resonant Half wave on 40m (7MHz) therefore also resonant on second, third and fourth harmonics. In order to do this, the load (antenna) must be balanced with respect to ground and other conductors. I had an email from a radio amateur who was struggling to work DX after putting up a very off centre fed dipole cut for 40m and fed with open wire feeder. Obviously, an EFHW antenna has a "half-wave" length only at one specific frequency: there is absolutely no such thing as a "multi-band end-fed half-wave" antenna. Unlike many END FED antennas on the market, this one does not require the Antenna Tuner to operate. At FT82-43 matching transformer for an EFHW I wrote about the likely losses at 3. com), a model by VE3KL and the spherical geometry technique used for the Bent Dipoles "Elevated Radials" study. Homebrew 10/20/40m EFHW vertical Antenna "SOTA". I may hang not just the center, but also the far end of the wire as high as possible to lower ground losses. Daniel S • February 17, 2019 2:08 AM It seems to me that the main problem is not that the cable has the properties it’s got, but that any device plugged in to the port automatically gets. Follow us on Facebook KENWOOD TM281A 65 Watt 2m Mobile $136. To continue with your YouTube experience, please fill out the form below. This is an End-Fed Half-Wave (EFHW*) antenna for 80/40/30/20/17/15/12 and 10m bands. Method Two SOTA aerials were set up in an urban surrounding in IO91ij. Easy Storage/transport. EFHW antena difeedpoint mempunyai sifat current minima, high voltage. ham radio - AFTER the zombie apocalypse, The prepp Ham Radio - Ground spike antenna. If the transformer box is installed high above the ground , there is no need to route the ground wire from the box, instead just ground the coaxial cable at the entrance to your home or at the station. Hamsticks are classified as helical wound 4 foot antennas that have a tuning tip on the end. COM Firearm Discussion Forums, Everything. The direction of radiation is the Blue trace on the polar graphs. EFHW-8010-P, EFHW-4010-1K etc. Post #1233. I added a couple of ground stakes near the base of the antenna, and added another surface radial 60 feet long for 80m. I may hang not just the center, but also the far end of the wire as high as possible to lower ground losses. EFHW matching transformer Сортировать Ascending Descending From A to Z From Z to A New-Old Old-New Показывать 15 24 33 90 100 Eur. 12 dBi down to 2. Hamsticks are classified as helical wound 4 foot antennas that have a tuning tip on the end. Using the earth 2m Backpacking Yagi. If the transformer box is installed high above the ground, there is no need to route the ground wire from the box, instead just ground the coaxial cable at the entrance to your home or at the station. By John Portune W6NBC. the coaxial feed line acts as a counterpoise, so no ground radial system is needed. Z of EFHW vs. A half-wave at the lowest band of interest will also work well on all harmonically-related bands which has become particularly attractive to those wanting a quick portable wire antenna. 2001 The 40 Meters band stealth vertical antenna by K7ZB “You’re 30dB over 9 here…” So goes the consistently fine signal reports received from around the USA and beyond – on 40 meters at the peak of Sun Spot Cycle 23. Ham Radio Station Grounding. The 7 band OCF Dipole antenna was erected at 25 to 30 feet, on a hill side, using a military style push up mast, with a few customization on it. I don’t have antenna simulation software on my MAC Air. The Balun matches the Balanced Antenna into the Unbalanced Coax Cable. I have been experimenting with feeding end fed half wave antennas matched by a parallel tuned circuit coupler. The 40m EFHW is physically broken into 3 sections via two insulators inserted so that the first (when viewed from the tuner end of the wire) isolates a 20m EFHW, the next section when added on via a jumper (I use alligator clips and spade lugs) is resonant on 30m and addding the last section makes it an EFHW on 40m. These antennas can be mounted horizontally, vertically or as a sloper. Dropping the ability to tune in 160m seems an acceptable trade-off for the advantage of having a shorter multiband end-fed antenna with no counterpoise cables on the ground. Power ratingsare in Watts PEP for SSB/CW modes, with 50% or less transmit time (ICAS). FULL HF Coverage, no tuner needed on most frequencies. Unlike many END FED antennas on the market, this one does not require the Antenna Tuner to operate. This page contains various javascript based calculators for electronics. 94 KB; Laser Communication Systems. If the transformer box is installed high above the ground, there is no need to route the ground wire from the box, instead just ground the coaxial cable at the entrance to your home or at the station. 5″) segments are then used as ground radials. Follow us on Facebook KENWOOD TMV71A 2m/70cm Mobile $344. 30 Watts QRP, 40-10 Meters, 66 feet. Although EFHW antennas are fairly simple and inexpensive, they do require a transformer to match the nominal 50 ohm impedance of your HF transceiver to the often high impedance (2500 ohm plus) of half wavelength wire antennas. EFHW antennas benefit from a connection to ground, just not for the reasons usually given. 6MHz of a common design using a FT82-43 ferrite core with a 3t primary. EFHW-8010P- 200W Portable or Stationary Multi-Band End Fed Half Wave Antenna This is a 200W version of popular EFHW-8010 End-Fed Half-Wave (EFHW*) antenna for 80/40/30/20/17/15/12 and 10m bands. 5MHz) therefore also resonant on second, third and fourth harmonics etc. The actual SWR for any installation is likely to be different. An antenna can get charged up in different ways. My new launcher worked beautifully. End-fed radiators have the unique quality of resonating on the 1/2-wave fundamental frequency plus odd/even harmonics above! Get on the air! Just one high center or end support -- installation is fast for home, road, emergencies. They also have become bathed in misinformation, mystique, and contradiction. When SWR is higher than 2:1 or antenna is used on the non-resonant frequency of the wire radiator, power reduction is recommended due to additional mismatch losses and the possibility to overheat the. Unlike many END FED antennas on the market, this one does not require the Antenna Tuner to operate. 94 KB; Laser Communication Systems. The far end was launched up at a height of about 25 feet into a tree. Connect a 3300 Ohm resistor from the top of the coil to the ground of the antenna plug. Setup the 20m EFHW as a vertical on the 30ft travel mast as before. MEF-330-1K Multiband EFHW Antenna Transformer, Covers 8 Bands / 80-10m / 1kW-max. I haven't found a better way to model an EFHW in NEC2. This is an End-Fed Half-Wave (EFHW*) antenna for 80/40/30/20/17/15/12 and 10m bands. Steve Yates - AA5TB HOME. Using the earth 2m Backpacking Yagi. 3:1) on 80m. The soil here is 99% clay about 8" down so it gets really unpleasant to work in quite quickly. My Station: Yaesu FT-1000, 135 foot Inverted L for 160/40, 180 foot dipole fed with ladder line to a Johnson Matchbox, KLM KT-34A at 50 feet. As you can see in the plot the swr is verry flat from 40-10m so a capacitor at the input is not needed. It requires no radials and has worked well for me. QRPGuys Portable 40-30-20m Tri-Band Vertical Antenna - $20 With permission from Joe Everhart, (N2CX), we have adapted his 40-30-20m portable vertical antenna design using switched toroids for the base loading inductance into a lightweight antenna for an easy outdoor setup. Some time ago I had several posts regarding an EFHW matchbox which I used to develop a linked end fed antenna as well as some other variations. Just asking. Quarter wave verticals for HF The radiation pattern for a quarter wave vertical. This item End Fed EFHW-4010-1K 40M-10M wire antenna Portable End-Fed 40-6 Meters Poly-Stealth Dipole Antenna Harvest Out 250B (3. 2m ground clearance, apex 1m below the top of pole (for stability) 84m was "guestimated" as the starting point for the overall size of the loop. Then use another torroid or several clamp on ferrites directly on the coax after the torroid so that the coax really now is RF free. Applying a feed to any antenna in NEC or any electromagnetic simulation software is about a simple a task as can be conceived by placing a “source” of near infinitesimal size inline with a dipole element. The only ground connected to the IC7300 is the regular station grounding system, where the IC7300 picks up a ground through the black wire of its power cord. I use about 20' of RG8x to the feed point at ground level, which has a 9:1 UnUn and is tied to a ground rod. Red color indicates the stronger radiation on 3D views. Do not ground the counterpoise stud when using a counterpoise(s) or radial field. A "portal" that hams think of as the first place to go for information, to exchange ideas, and be part of what's happening with ham radio on the Internet. Try adding a wire one-quarter wave long to the ground connection on the box for 17 and 12m. the wire diameter and the height about ground reports 65 Ohms, and the measured value is 61 Ohms, we can be more confident that we have built a form of what we modeled, and what is close to a textbook half wavelength dipole. So, sea all around. I added a couple of ground stakes near the base of the antenna, and added another surface radial 60 feet long for 80m. Unlike many END FED antennas on the market this one does not require the Antenna Tuner to operate. The EFHW - an efficient monoband end-fed half wave for 10m, 20m or any other HF band Update: A detailed description and construction details are now available for download (PDF). 4 metre length of silicon insulated 18 AWG multi-strand copper wire supported by a 9 metre telescopic pole. The soil here is 99% clay about 8" down so it gets really unpleasant to work in quite quickly. This is an End-Fed Half-Wave (EFHW*) antenna for 80/40/30/20/17/15/12 and 10m bands. SDRplay have recently posted a new workflow document and video that shows how to easily set up GNU Radio on Windows with an SDRplay software defined radio. Second, the high current part of the wire, which does most of the radiating, is a quarter wave from the feedpoint, which can usually be much higher than the feedpoint. 43 MB; LogiTalker Owners Manual. Presented is a method learned from other hams on how to install a ground rod with minimal or no hammering. EFHW End Fed Halfwave Antenna is a curation of 25 resources about , 20m Half-Wave End Fed, The EFHW Antenna, End Fed Half-Wave Antennas, EFHW matching unit, End Fed Half Wave Antenna Coupler. 2:1, a bit higher than the dipole however it remained the same across the entire 20m band whereas the dipole was quiet narrow. Installation of the 9:1 balun/unun: The End-Fed is connected to one terminal of the "high" winding and the other terminal is connected to a good "EARTH" ground. I was answering that I'd need to go up a tree to get to it. Add coax feedline -- get on the air!. 2dB but you will still have your needed 40% increase in power. Running about 40w from this hotel basement QTH on the west side of the island, I was easily working into the European continent on 40 and 20m in SSB. EFHW-8010-P, EFHW-4010-1K etc. (Chapt 21 page 16 of 2008 edition. The ground wiring and everything connected to it is every bit as much a part of the Marconi antenna system as is the live element. The above chart shows common SWR curves. I have one EFHW 130 foot antenna that is a horizontal antenna. The coax connector is at one end of the dipole, where it is most needed. The J-pole and other end-fed Hertz antennas are prime examples of antenna that can have severe feed line common mode current problems. There is no significant edge for the link dipole in performance. It is resonant Half wave on 80m (3. Here is a sure fire way to make end fed half wave antennas fed with a 50 ohm coupler work - without long radials, elaborate grounds, chokes, voodoo, etc. Do not ground the counterpoise stud when using a counterpoise(s) or radial field. Quarter wave verticals for HF The radiation pattern for a quarter wave vertical. Prune in the field for resonance of your choice. always heard that above ground radials work better than on the ground and at this location it plays very well Bob K3DJC Hello Mike. By John Portune W6NBC. One manufacturer of a popular EFHW antenna system that uses a 2/3 terminal matching device recommends that where the fed end of the dipole is elevated, that the match device be installed there and that the coax be grounded where it reaches ground. A vertical seemed the obvious answer, a naturally low-angle radiator. Somewhere on the internet I read that a small counterpoise is optimal, so chances are it was omitted in the design you mention to make the antenna smaller, or because it didn't offer a noticeable improvement. net is a Web site dedicated to ham radio (amateur radio). I have an MFJ-934 tuner/artificial ground for my MFJ-1699 multi-band vertical (stuck on a balcony, so limited HF antenna options), and I'm wondering if there's any downside to the counterpoise starting in the shack and then running outside to the balcony rather than at the base of the antenna itself. Video: EFHW Installation Summary or Is your feed line part of the antenna? Steve’s best test results were with the transformer grounded close to the ground and fed with enough coax to reach the transmitter also grounded. 102 feet long, shorter than 80 Meter dipole. I had flashbacks of digging this hole at the place in Wylie and I was nervous about it this go around. I bought an antenna much like an EFHW-4010 from a friend of mine and am hoping to get it work without having to bury a second cable for another antenna. I have one of the original PAR end fed half wave antennas prior to LNR taking over production and sales. 1 - EFHW antennas. This antenna so far has met my expectations and is weight comparable to other SOTA antennas I have. Then I ordered the Sotabeams Pico Tuner (at a very good price). In spite of what some manufacturers will tell you, an end-fed 1/2 wave ALWAYS has a counterpoise. It typically is configured as an inverted L for 160 meters, using a small BC variable in series at the feedpoint to tune for lowest SWR (using only 100 watts). I've settled on a EFHW-8010P from myantennas. It seems that at the heart of common ham understanding of this antenna system is that some kind of two terminal feed device creates a scenario. ground plane antenna with radials. Handles full legal limit power. ARDUINO ATU for EFHW 20/40m antenna & Icom TRX. A half-wave at the lowest band of interest will also work well on all harmonically-related bands which has become particularly attractive to those wanting a quick portable wire antenna. segmented dipole. Luckily the ground was relatively dry so it was just a matter of scraping and evacuating the hole repeatedly until I hit the magic number. If you are using a tuner that has just one wire coming out of it, then the other half is the tuner's chassis, and whatever is connected to it. G0KYA's HF End Fed Half Wave (EFHW) antenna - construction details Introduction The EFHW monoband matching unit (inspired by AA5TB) allows for a half wavelength of wire to be connected, giving a 50 Ohm impedance match to the transmitter (without a ground plane or ATU) at the frequency of operation. The Near Vertical Incident Skywave (NVIS) antenna is a half-wave dipole antenna mounted not over 1/8th wave above ground (at the highest operating frequency). También he experimentado con un hilo de 20 metros colocando el sobrante hacia abajo, en "V" invertida, con su correspondiente aislador casero y sujeto a una valla. One or more copper rods or pipes driven, at least, 4 feet into the earth near the dwelling entry point (2 or 3, is better, being spaced about 4 feet apart). Â As published in antennex Dec. Find many great new & used options and get the best deals for HF End Fed Antenna EFHW-8010-2K 2000W 80-10m / NO TUNER NEEDED!! / 130 feet long at the best online prices at eBay!. All I did was a) ground the matching. QRPGuys Portable 40-30-20m Tri-Band Vertical Antenna - $20 With permission from Joe Everhart, (N2CX), we have adapted his 40-30-20m portable vertical antenna design using switched toroids for the base loading inductance into a lightweight antenna for an easy outdoor setup. No the inverted L feed point is at ground zero. I have an MFJ-934 tuner/artificial ground for my MFJ-1699 multi-band vertical (stuck on a balcony, so limited HF antenna options), and I'm wondering if there's any downside to the counterpoise starting in the shack and then running outside to the balcony rather than at the base of the antenna itself. 2mm insulated wire run up one pole, across to the other then down the other. 5MHz) therefore also resonant on second, third and fourth harmonics etc. On Tuesday 8th August, there was a planned contact between the ISS and YOTA at 1837 UTC, so I decided to have a listen. Both radiate just the same amount of r. However, the real reason to DC ground an antenna has more to do with the following two possibilities. This describes the pictured EFHW (End Fed Half Wave) antenna in the photos below. I’d also take a pair of solder-less alligator clips (less than $1 each, many sources) and a solder-less 3. Here is a small collection of EZNEC files of antennas I have interest in. 1 VSWR on 160 meters all with NO TUNER !!. Various installations such as horizontal, vertical, as inverted V, as inverted L etc. Thus it will not be a good model of the radiation pattern when deployed as an inverted V, but seems to be OK to calculate lengths of wire segments. I like half wave dipoles. Basically, a piece of wire that is a half wavelength of the band you intend to operate. Homebrew 10/20/40m EFHW vertical Antenna "SOTA".